Early-Life Conditions and Cognitive Function in Middle-and Old-Aged Chinese Adults: A Longitudinal Study

A range of previous studies have suggested that early-life conditions (ELCs) are associated with various health problems throughout life in Western societies. The aim of this study was to investigate whether, and how, early-life conditions predicted the level and trajectory of cognitive function in middle- and old-aged Chinese adults. Data were obtained from China Health and Retirement Longitudinal Study which comprised 16,258 adults at baseline. Cognitive function was assessed using mental intactness and episodic memory and ELCs were measured by early parental death, childhood socioeconomic status (SES), food deprivation, and childhood health. Growth curve modeling was used to examine the trajectory of cognitive function (three waves in a 6-year period)with particular attention paid to the effects of ELCs on cognition. The results show that early maternal death is associated with the baseline cognitive level among middle- and old-aged Chinese adults (β range between −0.44 and −0.35, p < 0.05), but that this association is also largely attenuated by adulthood education. Higher childhood SES predicts an enhanced level of baseline cognition in both age groups (β range between 0.08 and 1.27, p < 0.001), but only protects against cognitive decline at baseline in middle-aged adults. Participants who were less healthy during childhood tended to have lower cognitive performance than those who had enjoyed good health (β range between −0.36 and −0.14, p < 0.05). The results of this study highlight the detrimental impact of deleterious ELCs on cognitive function throughout later life.